Antenna



FIG. 1 is a top plan view of an antenna, showing our new design with an unclaimed base drawn in broken line;

FIG. 2 is a side elevation view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a rear plan view thereof;

FIG. 6 is a front elevation view of the antenna; and,

FIG. 7 is a side elevation view of the antenna.

The broken lines illustrate environment that forms no part of the claimed design. 

CLAIM The ornamental design for an antenna, as shown and described. 